1. Field of the Invention
The present invention relates to an elastic sheet and a switch using the elastic sheet, and particularly to an elastic sheet and a switch using the elastic sheet applied in consumer electronic applications.
2. Description of the Prior Art
A conventional elastic sheet and a switch using the sheet are disclosed in FIGS.1-3. The elastic sheet comprises a first sheet 10′ plated with a metal film 11′, a plurality of curved moveable contacts 20′ attached to a bottom surface of the first sheet contact 10′, a second sheet 30′ attached on a bottom surface of the first sheet 10′ and defining a plurality of receptacle holes 31′ for receiving the moveable contacts 20′, a separator sheet 40′ affixed on a bottom surface of the second sheet 30′. The second sheet 30′ defines a plurality of connecting slot 32′ connecting the adjacent receptacle holes 31′ for air circulation. The first sheet 10′, the second sheet 30′ and the separator sheet 40′ define respectively a first extending portion 12′, a second extending portion 33′ and a third extending portion 41′, wherein the first extending portion 12′ and the second extending portion 33′ bend towards the second sheet 30′.
A switch using the elastic sheet 5′ comprise the elastic sheet 5′ and a circuit board 6′. In assembling, the separator sheet 40′ is peeled from the bottom surface of the second sheet 30′. The elastic sheet 5′ is attached to the circuit board 6′ by an adhesive on the bottom surface of the second sheet 30′. The circuit board 6′ defines a plurality of outer fixed contacts 61′ and a central fixed contacts 62′, wherein the outer fixed contacts 61′ are defined on outside of the circuit and the central fixed contacts are defined on inside of the circuit. Each fringe portion of the moveable contact abuts against the first fixed contact and the center portion of the moveable contact is separated with the second fixed contact. Referring to FIG. 2, the first extending portion 12′ and the second extending portion 33′ bend along the line A-A, and then connect to the circuit board 6′ far contacting a ground end 63′ thereof, which can realize the discharge of static electricity.
However, the drawback of said elastic sheet 5′ lies in: when the first sheet 10′ and the second sheet 30′ are bent toward the second sheet 30′, since the first sheet 10′ is disposed on the second sheet 30′ the metal film 11′ plated on the first sheet 10′ generates a deformation, which is prone to be torn apart. If the metal film 11′ is torn apart, the static conducting test can not be attained or the heat produced during the static test makes the metal film 11′ split
Hence, an improved elastic sheet and a switch using the elastic sheet are required to overcome the disadvantages of the prior art.